Field
Embodiments of the present disclosure generally relate to hydraulically activated pump.
Description of the Related Art
When reservoir pressure in a well is insufficient for the production fluid to reach the surface on its own, pumps can be used in the well to help bring production fluids to the surface. One type of pump for such operations is a hydraulically actuated pump.
A hydraulically actuated pump is typically deployed downhole in a tubing disposed in a wellbore. Surface equipment injects power fluid, e.g., produced water or oil, down the tubing to the pump. The power fluid operates to drive an engine piston internally between upstrokes and down strokes which, in turn, drives a pump piston connected to the engine piston via a rod. During upstrokes, the pump draws in production fluid to an intake pump volume below the pump piston. During down strokes, the pump transfers the production fluid from the intake pump volume to a discharge pump volume above the pump piston. In a subsequent upstroke, the production fluid is discharged from the discharge pump volume via the tubing-casing annulus or some such parallel path to the surface equipment for handling.
Hydraulically activated pumps use the incompressible characteristic of the production liquid to transfer the production liquid from the intake volume to the discharge volume and discharge the production liquid out of the discharge volume. However, in traditional hydraulically activated pumps, when gas is drawn into the intake pump volume during an upstroke, the gas in the intake volume will simply compress and expand during the subsequent down strokes and upstrokes, thereby causing the pump to gas lock. When gas lock occurs, the pump fails to move any production liquid to the surface.
There is, therefore, a need for a hydraulic pump capable of preventing gas lock.